Solenoid actuated valve assemblies are commonly used to move an armature toward or away from a valve seat to control the flow of fluid. One application is in fuel pumps in gas stations, where a manifold block includes one or more valves, each of which is controlled by a solenoid assembly and normally in a closed position. The valves each include an armature which is operatively connected to a valve member, and is responsive to the energization of the, solenoid such that the valve member moves into an open position when the solenoid is actuated to dispense the gasoline. In applications where flammable vapor is present, the solenoid must be separated from the vapor to prevent ignition, and generally qualified for use in a hazardous location. This can include stringent and rigorous tests for torque, bending moment and pull per UL/NEC specifications. Conduit connections must also be evaluated for flame propagation.
To achieve the above, typically the conduit of the assembly is plumbed through a vapor barrier that separates the hazardous area (where vapors may be present) from the non-hazardous area. The lead wires for the solenoid are routed through the conduit to the control circuitry. The conduit and any fittings must be qualified as explosion-proof, but even so, are not considered to be vapor-tight. All passages (such as internal to the conduit) are potted with appropriate epoxy to prevent the vapors from passing through the conduit to the non-hazardous area. This all adds time and expense in manufacturing and assembling the solenoid assembly, increases the complexity of manufacture, and generally increases the cost in manufacturing the solenoid assembly. As such, it is believed there is a demand in the industry for a solenoid-controlled valve assembly which can be used in hazardous situations without i) having to go through a rigorous qualification process for conformance to explosion-proof conduit systems; and ii) required potting of a conduit system that is not vapor-tight.